What is network topology? Explain star and mesh topology with the help of suitable diagrams.

Network Topology is the arrangement of various elements (links, nodes, etc.) in a computer network. It defines how different network devices are connected and how data is transmitted between them.

Star Topology:

• Structure: All devices are connected to a central hub or switch.
• Advantages: Easy to install and manage; failure of one device doesn't affect others.
• Disadvantages: If the central hub fails, the entire network is disrupted.

Diagram:

      [PC1]
        |
        |
[PC2]--[Switch]--[PC3]
        |
        |
      [PC4]

Mesh Topology:

• Structure: Every device is connected to every other device.
• Advantages: High redundancy and reliability; failure of one device doesn't affect the network.
• Disadvantages: Expensive and complex to install and maintain due to numerous connections.

Diagram:

[PC1]-----[PC2]
  | \       |  \
  |  \      |   \
  |   \     |    \
[PC3]-----[PC4]
  | \    / |  \  /
  |  \  /  |   \/
[PC5]-----[PC6]

Star topology is commonly used in LANs for its simplicity, while mesh topology is used in mission-critical networks requiring high availability.